1. Field of the invention
This invention relates to a moving coil type (MC type) cartridge.
2. Description of the prior art
FIG. 1 shows a structure of a conventional moving coil type cartridge in which a magnetic circuit is formed by a magnet 1, yokes 2 and 3 and an air gap 4 disposed between the yokes 2 and 3. In addition, a cantilever 7 to which a needle or stylus 5 is attached with a given angle at one end and an armature coil 6 is integrally disposed at the other end is movably mounted to the yoke 3 by means of a tension wire 8 with its other end utilized as a fulcrum of movement. With the aforesaid coil 6 vibrated or rotated within the magnetic field of the air gap 4, a some amount of voltage will be induced in the coil 6 since the coil 6 cuts the magnetic flux. In short, in such a conventional system as this, a transducing system which is proportional to the moving speed of the armature is adopted.
However, in such a conventional moving coil type cartridge as mentioned above, a relatively large number of cartridge parts are required to lead the magnetic flux from the S or N pole of the magnet 1 through the yokes 2 and 3, thus making the cartridge itself bulky. In addition, the yokes 2 and 3 used for forming the magnetic circuit must be machined as precisely as possible, so that it is inevitable that the manufacturing cost of the cartridge becomes expensive.